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33 lines
874 B
C++
33 lines
874 B
C++
#pragma once
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#include <Core/SortDescription.h>
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#include <Storages/MergeTree/MergeTreeData.h>
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#include <Storages/SelectQueryInfo.h>
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namespace DB
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{
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/** Helper class, that can analyze MergeTree order key
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* and required sort description to get their
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* common prefix, which is needed for
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* performing reading in order of PK.
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*/
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class ReadInOrderOptimizer
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{
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public:
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ReadInOrderOptimizer(
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const ManyExpressionActions & elements_actions,
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const SortDescription & required_sort_description,
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const SyntaxAnalyzerResultPtr & syntax_result);
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InputSortingInfoPtr getInputOrder(const StoragePtr & storage) const;
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private:
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/// Actions for every element of order expression to analyze functions for monotonicicy
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ManyExpressionActions elements_actions;
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NameSet forbidden_columns;
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SortDescription required_sort_description;
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};
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}
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